The use of the bow and arrow is traced to the Upper Paleolithic or Late Stone Age from between 50,000 and 10,000 years ago. At the onset of the Late Stone Age there was a marked increase in the diversity of artifacts including projectile points. The diversity of projectile points indicated the desire to increase the efficiency of the projectile, since mankind's survival depended on his ability to hunt and bring down game. This consistent effort to improve the efficiency of projectile points extends to this day.
The killing efficiency of an arrow point is a function of its ability to penetrate the target and to deliver a wide cutting edge in order to cleanly sever major blood vessels and organs. The wide cutting edge was originally seen in the fixed blade version of the broad head arrow type. However, those types of broad heads were subject to cross winds diminishing accuracy. As a result, broad heads with folding blades began to be developed recognizing the aerodynamic advantages. The term “target” is used in this application to refer to any material the arrowhead may encounter. The greater the penetration, the greater the damage and the more quickly the animal succumbs. The prior art uniformly attempts to solve the problem of penetration by merely using a sharpened point and relying on the kinetic energy imparted by the bow which dissipates upon entering the target. This can be seen in U.S. Pat. No. 5,322,297 to Smith. Here, a standard point is utilized for initial penetration but no function is described that would enhance target penetration after the arrow head enters the target by preserving kinetic energy. Slots are used in both Smith and U.S. Pat. No. 6,200,237 B1 to Barrie, in which the proximal edge of the blades ride during deployment. After deployment, an open slot remains in front of the proximal edge of the blades which is susceptible to clogging with animal hair, fat and muscle. This may prevent the blades from folding and redeploying. In the prior art, the blades when in the folded position rest perpendicular and on top of the shafts, allowing aerodynamic interference. Barrie also utilized a standard point but does not indicate any aspect that would help preserve kinetic energy as the arrow travels through the target and offers no suggestion of a mechanism to overcome the problem of deflecting around or penetrating through resistant target material such as bone and cartilage which is the most common cause of poor penetration. Further the sliding body, (blade carrier in the applicant's embodiment) of Barrie has a stepped leading edge and will not allow blunt force impact. The prior art also discloses blades that when in the folded flight position, extend to some degree beyond the body of the arrowhead. This allows for aerodynamic interference from flight itself and from cross winds. The embodiment herein described recognizes that penetration can be maximized with utilization of the described design and material components.